Field of the Invention
The present invention relates to a method for producing a skin-covered polyolefin-based resin foamed molded article that is used as, for example, an automobile interior material. More specifically, the present invention relates to a method for producing a skin-covered polyolefin-based resin foamed molded article including the steps of forming a hollow, polyolefin-based resin molded body (namely a skin defining a hollow interior space) by blow molding, filling polyolefin-based resin expanded beads in the hollow interior space, and supplying a heating medium into the hollow interior space to fuse-bond the expanded beads to each other and to form a foamed molded article of the expanded beads (namely a foam layer) fuse-bonded to and covered with the skin.
Description of Prior Art
A skin-covered polyolefin-based resin foamed molded article obtained by filling expanded beads in a hollow interior space defined by a skin and introducing a heating medium into the hollow interior space to fuse-bond the expanded beads to each other and to the skin, and a method for the production thereof are heretofore known. Specifically, as a method for producing the skin-covered polyolefin-based resin foamed molded article, there is a method as described below.
Namely, a parison in a softened state extruded from an extruder is placed in a mold for blow molding. Then, pressurized air is blown into the parison to blow-mold the parison into a skin defining a hollow interior space. Then, expanded beads are filled in the hollow interior space, and a heating medium is introduced into the hollow interior space to heat the expanded beads and to cause the expanded beads to fuse-bond to each other. After cooling, the product is taken out of the mold to obtain a skin-covered polyolefin-based resin foamed molded article.
For example, Japanese Patent No. JP-B-2860007 derived from JP-A-H06 (1994)-166112 discloses a method for producing a skin-covered polyolefin-based resin foamed molded article including the steps of blow molding a skin defining therein a hollow interior space, filling expanded beads in the hollow interior space before the skin cools and hardens, and heating the expanded beads with a heating medium to fuse-bond the expanded beads to each other. Specifically, in order to fill the expanded beads in the hollow interior space efficiently, a hole is formed through the skin so that the hollow interior space can be open to the atmosphere when the expanded beads are filled in the hollow interior space.
Japanese Patent Publication No. JP-A-2004-249558 discloses a skin-covered foamed molded article produced using expanded beads and a method for producing the foamed molded article. The expanded beads each have an expanded core layer formed of a resin and a non-expanded cover layer covering the core layer and formed of a resin having a melting point or softening point lower than that of the resin forming the core layer.